1. Field of the Invention
The present invention relates to a program product for linking operations between multiple devices connected to each other via a network, and to a connected device that serves to link operations between the multiple connected devices.
2. Description of the Related Art
There are proposed methods for linking operations between multiple devices connected to each other via a network. For example, Japanese laid-open patent publication 2002-186067 discloses an electric appliance control device that is designed to control all electric appliances connected thereto such as a television receiver, an air conditioner, and a telephone by receiving a control command from one of the electric appliances via a communication line, storing the received control command in a code memory provided in a control signal sending/receiving unit, and sending the control command received from the electric appliance, which is stored in the code memory, from an infrared transmitter/receiver in the control signal sending/receiving unit. This device enables linked operations such as turning down the volume on the television receiver in response to a telephone call.
However, the above described electric appliance control device has the following problem. When an event (e.g. an incoming call) occurs at an external device (e.g., the telephone), the control device always performs a process for a device (e.g., the television receiver) that is to operate in conjunction with the external device (such a device is hereinafter referred to as “linked device”) without respect to the state of the linked device. For example, even when there is no audio signal input to the television receiver at the time of the incoming call, the control device may perform the process for turning down the volume on the television receiver. As another example, assume that the control device has been programmed to cause a hard disk drive (HDD) recorder to automatically start recording when a call at the telephone lasts more than a given time. In this case, when the given time has elapsed from the start of a call at the telephone, the control device may perform the process for causing the HDD recorder to automatically start recording even when the HDD recorder is already during recording. Accordingly, the electric appliance control device disclosed in Japanese laid-open patent publication 2002-186067 cannot always allow linked operations to be performed as a user truly desires. Further, the electric appliance control device disclosed in Japanese laid-open patent publication 2002-186067 has a problem that it requires the above described control signal sending/receiving unit as well as a dedicated device (such as a personal computer) as the electric appliance control device.
Japanese laid-open patent publication 2004-304789 discloses an electric appliance control device and an electric appliance control method for, when receiving from a user the designation of an appliance in a state different from a state desired by the user, identifying a linked operation to be modified based on a linked operation table, appliance history information, and so on and then modifying the linked operation table so that the appliance can be in the desired state at a reference time.
Further, Japanese laid-open patent publication 2004-258809 discloses a middleware for information appliance networks that, upon receipt of a service request from a user, activates a service component corresponding to the requested service in accordance with service component information contained in a look-up table.
However, the inventions disclosed in Japanese laid-open patent publication Nos. 2004-304789 and 2004-258809 always perform an operation for a linked device without respect to the state of the linked device when an event occurs at an external device. Accordingly, neither of the inventions allows linked operations to be always performed as a user truly desires.